When develop embed device, the hardest part is debug weird issue. It is because the bug is very hard to locate, it might be hardware, kernel, or application. Currently the record audio bug is absolutely a weird bug.

But I finally get it!

Bug and me are good friends, we like to play “hide and seek”, if it wins, it is free to drink my blood; if I win, I kill it!

It is because ES8388 ADC require DAC to work, what the design…It is absolutely a chip bug.

Now it works perfectly, recorded sound is very clear. 🙂
And alsamixer is working fine too.